System for trapping flying insects and a method for making the same

ABSTRACT

A flying insect trapping device configured to be used with a fuel supply containing combustible fuel. The device may include a supporting frame; an insect trap chamber carried on the supporting frame; and a combustion device which may also be carried on the supporting frame. The combustion device comprises an inlet port for connection with the fuel supply, an exhaust port, and a combustion chamber communicating the inlet port with the exhaust port. The inlet port enables the fuel from the fuel supply to flow into the combustion chamber for continuous combustion therein to create an exhaust gas within the combustion chamber. The combustion device further includes a catalyst element disposed within the combustion chamber. The catalyst element has a catalyst body with a plurality of essentially linear elongated conduits for enabling the exhaust gas created in the combustion chamber to flow therethrough towards the exhaust port. The catalyst body includes a catalytically active material that, during operation, converts carbon monoxide in the exhaust gas to carbon dioxide as the exhaust gas flows through the elongated conduits. An insect inlet is communicated with the insect trap chamber to enable flying insects to enter the trap chamber through the insect inlet. A vacuum device communicated to the insect inlet is constructed and arranged to draw insects attracted to the exhaust outlet through the insect inlet and into the insect trap chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.10/264,260, filed on Oct. 4, 2002, which, in turn, relies upon andclaims the benefit of the filing date of U.S. Provisional ApplicationNo. 60/326,722, filed Oct. 4, 2001, the contents of both of which areincorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for trapping flying insects,such as mosquitoes, no-see-ums, and other insects that are attracted tocarbon dioxide emanating from mammals.

2. Description of Related Art

Each year mosquito-transmitted diseases are responsible for over 3million deaths and 300 million clinical cases. It is estimated that theworldwide costs associated with the treatment of suchmosquito-transmitted diseases runs well into the billions of dollars. Inmany regions mosquitoes are the primary transmitters of debilitatingdiseases such as malaria, yellow fever, dengue fever, encephalitis, WestNile virus, sleeping sickness, filariasis, typhus and plague. Inaddition to the illnesses and deaths caused to humans,mosquito-transmitted diseases are a major cause of economic losses tolivestock industries due to veterinary diseases. Further,mosquito-transmitted diseases pose an ever-present concern to regionsdependent on revenues from tourism. Specifically, the presence of suchdiseases in a given region is believed to impact the willingness oftourists to select that region as a tourism destination.

With increased travel and world commerce it also is expected that someof these diseases will become major health problems in the continentalUnited States and elsewhere. For example, the emergence of the West Nilevirus in temperate regions of Europe and North America supports thisexpectation, which represents a threat to public, equine and animalhealth. It can result in encephalitis (inflammation of the brain) inhumans and horses, and mortality in domestic animals and wild birds.

In 1995, endemic cases of malaria were recorded in California and NewJersey, and several cases of dengue fever were diagnosed in southernTexas. In September 1996, an unprecedented number of mosquitoes werefound in Rhode Island carrying Eastern Equine Encephalitis. Test resultsrevealed that one out of 100 mosquitoes trapped were carrying this rare,deadly virus that has a mortality rate of 30%-60%. The situation inRhode Island was so severe that the governor declared a state ofemergency. In 1997, a similar situation occurred in Florida with anoutbreak of St. Louis Encephalitis.

Dengue fever is a particularly dangerous mosquito-transmitted diseasethat is increasingly becoming a problem of global proportions and maysoon eclipse malaria as the most significant mosquito-borne viraldisease affecting humans. Dengue fever's global distribution iscomparable to that of malaria, with an estimated 2.5 billion peopleliving in areas at risk for epidemic transmission. Each year, millionsof cases occur, and up to hundreds of thousands of cases of denguehemorrhagic fever (DHF) are diagnosed. The case-fatality rate of DHF inmost countries is about 5%, with most fatal cases occurring amongchildren.

Until recently, dengue fever was relatively unknown in the WesternHemisphere. In the 1970s, a dengue epidemic swept through Cuba and otherparts of the Caribbean. In 1981, a second serotype, which wasaccompanied by hemorrhagic fever, broke out in Cuba. That secondepidemic resulted in more than 300,000 hemorrhagic fever cases, and morethan 1,000 deaths, most of which were children. By 1986, other countriesin South America and Mexico began to see a significant rise in denguefever. The summer of 1998 saw a new outbreak on the island of Barbados.

With respect to the mainland Americas, nearly 24,000 cases of denguefever were reported during the first eight months of 1995 in CentralAmerica, including 352 cases of hemorrhagic fever. El Salvador declareda national emergency due to the widespread infestation of this diseasein that country in 1995. Even Mexico recorded approximately 2,000 casesin 1995, 34 of which included hemorrhagic fever. In total, the PanAmerican Health Organization reported that there have been almost200,000 cases of dengue and more than 5,500 cases of hemorrhagic denguefever in the Americas. FIG. 1A is provided to illustrate the worldwidedistribution of dengue in the year 2000, and FIG. 1B is provided toillustrate the recent increase in dengue cases reported in the Americas.

Entomologists are very concerned about the increased threat of denguefever to the United States. This concern is attributable in part to thepresence of the recently arrived species of mosquito known as the Aedesalbopictus. Aedes albopictus (also called the “tiger mosquito” due toits bright striping and aggressive biting) was first discovered in theUnited States in 1985 in Harris County, Texas. Historically, the tigermosquito has been a major transmitter of dengue fever in Asia. However,it is believed that the introduction of the tiger mosquito in the UnitedStates can be traced to a shipment of old tires from Japan. In 1991, theEastern Equine Encephalitis virus was discovered in groups of tigermosquitoes found in a tire pile just 12 miles west of Walt Disney Worldin Orlando, Fla.

As of February 1996, established populations of the tiger mosquito havebeen documented in 24 states. Most alarming is that the tiger mosquitohas now demonstrated the ability to survive in states as far north asOhio, New Jersey, and Nebraska Unlike the Aedes aegypti, the tigermosquito's eggs can survive very cold winters. As a result, the tigermosquito has great potential to carry diseases into a substantialportion of the United States. The tiger mosquito is already proving anuisance and hazard in Pulaski County, Illinois, where bite counts ofthe insect were 25 per minute. In the Central region of the UnitedStates, this species has been linked to the transmission of La CrosseEncephalitis, an often fatal disease.

To illustrate the distribution of these mosquito-borne illnesses withinthe United States, attached FIGS. 1C through 1F are provided. FIG. 1Cillustrates the distribution of confirmed and probable human LaCrosseencephalitis cases between 1964 and 1997 in the United States. FIG. 1Dillustrates the distribution of human St. Louis Encephalitis casesbetween 1964 and 1998 in the United States; FIG. 1E illustrates thedistribution of confirmed and probable human Western Equine Encephalitiscases between 1964 and 1997 in the United States; and FIG. 1Fillustrates the distribution of confirmed and probable human EasternEquine Encephalitis cases between 1964 and 1997 in the United States. Ascan be seen from these Figures, the distribution of these diseases iswidespread throughout the United States, thus, leading to the presentpublic concern over further spread of these diseases.

A number of methods for controlling mosquito populations or repellingmosquitoes have been proposed in the past. Examples of these arediscussed hereinbelow. As will be appreciated from the followingdiscussion, each of these methods have significant drawbacks whichrender them impractical or ineffective.

One well-known method for suppressing mosquito populations is the use ofchemical pesticides, such as DDT and Malathion. There are basically twotypes of mosquito pesticides available—adulticides and larvicides.Adulticides are chemicals used to kill mosquitoes that have developed tothe adult stage. Infested areas are primarily sprayed from aircraft ormotor vehicles. Efficacy of the sprayed chemicals is typically dependentupon wind, temperature, humidity, and time of day, the particularmosquito's resistance to the chemical used, and the base efficacy of theparticular chemical. Adulticides must be applied for each generation ofadults produced by rain, tidal flooding, or other periodic egg hatchingtrigger, and have a typical efficacy window of only ½ day. As such,these chemicals must be applied at a time when maximum contact withadult mosquitoes can be expected.

Larvicides, on the other hand, are applied to water sources to kill thelarvae before they become adult mosquitoes. Larvicides generally takethe form of one of three varieties: (1) an oil applied to the watersurface that prevents the larvae from breathing and thus drowns them,(2) a bacteria, like BTI (bacillus thuringiensis israelensis), whichattacks the larvae and kills them, or (3) a chemical insect growthregulator (e.g. methoprene) that prevents the larvae from developing tothe adult stage. However, larvicides are often not particularlyeffective for a variety of reasons. For example, most larvicides have ashort efficacy period and must be applied to the water while theimmature mosquitoes are at a particular stage of growth. Also, severalspecies of mosquitoes, such as tree-hole breeders, root-swamp breeders,and cattail-marsh breeders, are not easily controlled with larvicidessince the larvae either do not come to the surface (e.g., cattail marshmosquito) or the water sources are so difficult to locate that thelarvicide's cannot be economically applied (e.g., tree holes).Additionally, the mosquito that carries the West Nile virus (CulexPippiens) lives and breeds around humans in gutters, underground drains,flower pots, birdbaths, etc. This not only makes the spraying ofinsecticides impractical due to the difficulty associated witheffectively targeting such areas, many people are also uncomfortablewith the use of chemical pesticides so close to their homes.

Regardless of their alleged efficacy, or lack thereof, the use ofchemical pesticides has been reduced dramatically in both the UnitedStates and worldwide. A primary reason for this reduction isattributable to the rising public awareness of the potential healthhazards related to pesticide use. Specifically, general publicperception of the long-term health hazards presented by certainchemicals, such as DDT, has led to the banning of their use for mosquitocontrol in many parts of the United States and other countries.Additionally, increasing pesticide resistance among mosquitoes hasreduced the effectiveness of the chemicals conventionally used, thusbolstering the argument that the supposed benefits of chemicalpesticides do not outweigh public health risks.

To some extent, natural predators also control mosquito populations. Forexample, certain fish and dragonflies (as both nymphs and adults) arereported to be predacious to mosquito larvae and adults. Additionally,it is known that certain bats and birds also prey on mosquitoes. It hasbeen advocated by some people, particularly those opposed to the use ofchemical pesticides, that natural predators should be relied on as anenvironmentally safe means of controlling mosquito populations.Unfortunately, efforts in the past to utilize natural predators foreffectively controlling mosquito populations have proven ineffective.For example, large bat towers were erected in three cities in the Southduring the 1920's with high expectations that the bats living in thesetowers would control mosquito populations. However, these towers wereineffective at adequately controlling the local mosquito populations.Studies of the stomach contents of the bats found that mosquitoes madeup less than 1% of their food source.

Many people rely on repellents to keep mosquitoes away from theirperson, or from a certain area. These repellents by their nature donothing to actually control the mosquito population; instead, theysimply offer temporary relief to the person employing the repellent.Repellents can be either topical or aerial, and can take many forms,including lotions, sprays, oils-(i.e. “Skin-So-Soft”), coils, andcandles (e.g. citronella), among others. The most common repellents(lotions, sprays, and oils) are those that are used on the clothing orbody. Many of these repellents do not actually “repel” mosquitoes perse—instead, some repellents simply mask the factors (carbon dioxide,moisture, warmth and lactic acid), which attract a mosquito to its host.Although these repellents are fairly inexpensive, they often have anoffensive odor, are greasy, and are effective for only a limitedduration. It has also been found that repellents, which contain DEET, orethyl hexanediol, actually become attractive to mosquitoes after aperiod of time. Therefore, it is advisable when using repellents to washthem off or reapply fresh repellent when the protective period haspassed.

In addition to being unpleasant, many repellents are coming under closescrutiny with respect to the potential long-term health hazards they maypose. DEET, considered by many entomologists to be the best repellentavailable, has been marketed for over 30 years, and is the primaryingredient of many well-known commercial sprays and lotions. Despite thelong-term widespread use of DEET, the U.S. Environmental ProtectionAgency (EPA) believes that DEET may have the ability to cause cancers,birth defects, and reproductive problems. In fact, the EPA issued aconsumer bulletin in August 1990 in which they stated that a smallsegment of the population may be sensitive to DEET. Repeatedapplications—particularly on small children—may sometimes causeheadaches, mood changes, confusion, nausea, muscle spasms, convulsionsor unconsciousness.

Mosquito coils have been sold for many years as a means for repellingmosquitoes. These coils are burnt to emit a repellent smoke. Productsmanufactured some 20 years ago were under the trade name Raid MosquitoCoils and contained the chemical Allethrin. Recent products are tradenamed OFF Yard & Patio Bug Barriers and contain the chemical Esbiothrin.These products may provide some relief from mosquito activity; however,they do not reduce the number of mosquitoes in a region, and they emitsmoke and chemicals into the vicinity. Also, with even the slightestbreeze, their potential effect is diminished, as the smoke and chemicalsare dispersed over a large area and thus become diluted and lesseffective.

Many people have also touted the benefits of citronella in repellingmosquitoes, whether it is in the form of candles, plants, incense, orother mechanisms. According to a recent study, citronella-based productshave been shown to be only mildly effective in repelling mosquitoes andthen only when the candles were placed every three feet around aprotected area. This treatment was only slightly more effective thanburning plain candles around a protected area. In fact, it is believedthat burning the candles increases the amount of carbon dioxide in theair, causing more mosquitoes to be drawn into the general area ratherthan reducing the number of mosquitoes in the area. Despite thesedrawbacks, the current market for citronella-based products is quitelarge.

Introduced in the late 1970's, the familiar “black-light” electrocutiondevices, referred to as “bug zappers,” were initially a commercialsuccess. Although totally ineffective at killing mosquitoes, bug zapperssell at a current rate of over 2,000,000 units annually. The inabilityof these devices to kill mosquitoes has been proven in academic studiesand the personal experiences of many bug zapper owners. Specifically,electrocution devices do not kill mosquitoes because they do not attractmost types of mosquitoes. The reason for this is that these devices onlyattract insects that are attracted to light, which is not the case withmost types of mosquitoes.

U.S. Pat. No. 6,145,243 (“the '243 patent”) discloses an insect trappingdevice developed by the assignee of the present application, AmericanBiophysics Corporation of East Greenwich, R.I. The device of the '243patent discloses the basic construction of a device that generates aflow of carbon dioxide for attracting mosquitoes and other flyinginsects towards an inlet on the device. A vacuum draws the insectsattracted by the carbon dioxide through the inlet and into a trapchamber. The trap chamber includes a disposable mesh bag in which themosquitoes become dehydrated. When the bag becomes full, it can beremoved and replaced.

While the device disclosed in the 243 patent has been commerciallysuccessful for American Biophysics Corporation, further productdevelopment efforts by the inventors of the present application haveyielded a number of improvements that are directed to reduce themanufacturing costs and operational efficiency of the device of the '243patent. As a result of these improvements, the cost structure of thedevice of the present application can be reduced, thus making thetechnology more widely available to the average consumer. By making thistechnology available to more consumers, it is believed that the additiveimpact of widespread use of this technology will help lead to bettercontrol of mosquito and other flying insect populations and, in turn, toreduced incidents of insect transmitted diseases.

SUMMARY OF THE INVENTION

Turning now to the present invention, a first aspect of the presentinvention provides a flying insect trapping device having anadvantageous catalyst element. The device is configured to be used witha fuel supply containing combustible fuel. The device comprises asupporting frame; an insect trap chamber carried on the supportingframe; and a combustion device carried on the supporting frame. Thecombustion device comprises an inlet port for connection with the fuelsupply, an exhaust port, and a combustion chamber communicating theinlet port with the exhaust port. The inlet port enables the fuel fromthe fuel supply to flow into the combustion chamber for continuouscombustion therein to create an exhaust gas within the combustionchamber. The combustion device further comprises a catalyst elementdisposed within the combustion chamber. The catalyst element has acatalyst body with a plurality of essentially linear elongated conduitsfor enabling the exhaust gas created in the combustion chamber to flowtherethrough towards the exhaust port. The catalyst body includes acatalytically active material that, during operation, converts carbonmonoxide in the exhaust gas to carbon dioxide as the exhaust gas flowsthrough the elongated conduits.

An exhaust outlet is carried on the frame and is communicated with theexhaust port of the combustion device. The exhaust port allows theexhaust gas to flow outwardly through the exhaust outlet so that insectsattracted to the carbon dioxide in the exhaust gas will fly towards theexhaust outlet. An insect inlet is communicated with the insect trapchamber to enable flying insects to enter the trap chamber through theinsect inlet. A vacuum device communicated to the insect inlet isconstructed and arranged to draw insects attracted to the exhaust outletthrough the insect inlet and into the insect trap chamber.

The advantage of this aspect of the invention is the provision of thecatalyst body with the plurality of essentially linear elongatedconduits. This construction provides for an improved catalyticconversion over the specific preferred embodiment disclosed in theaforementioned '243 patent. Specifically, in the '243 patent, thecatalyst element was provided by a series of catalyst-coated spheresloosely entrapped in a defined space. The problem with this arrangementis that consistency in the catalytic conversion reaction was difficultto achieve on a mass production basis. That is, the effectiveness of thecatalytic conversion tended to vary between devices. It is believed thatthis is because using spheres caused a significant amount of turbulencein the air flowing therethrough and also loose packing of the spheresresulted in inconsistencies in the amount of catalytic surface areaexposed to the exhaust gas. Much fine tuning of the proper fuel and airmixture was required to ensure that the carbon monoxide levels weremaintained at a minimum in the commercial embodiment of the devicedisclosed in the '243 patent. Using the catalyst element mentioned aboveis believed to be an improvement over the construction of the device onthe '243 patent because it provides for improved consistency incatalytic conversion between devices. This improvement, in turn, leadsto reduced costs as it reduces and may even eliminate the need for finetuning the fuel/air mixture.

In a preferred feature of this aspect of the invention, the combustiondevice further comprises turbulence reducing structure disposed withinthe combustion chamber upstream of said catalyst element. The turbulencereducing structure has a plurality of apertures oriented in the samegeneral direction as the conduits of the catalyst body. The aperturesare configured to straighten the flow of fuel from the inlet port tothereby reduce turbulence in the fuel. This is desirable to improve theconsistency of the combustion operation. Specifically, in highlyturbulent flow, “pockets” of fuel may be created which will pass throughthe combustion chamber unburned. This is undesirable because unburnedfuel in the resultant exhaust gas is believed to be an insect repellent.By providing turbulence reducing structure, the flow's turbulence isthereby reduced and thus helps to minimize or eliminate the amount ofunburned fuel in the exhaust gas.

In a further preferred feature of this first aspect of the invention,the turbulence reducing structure comprises a catalytically inactivebody and the apertures of the turbulence reducing structure comprise aplurality of essentially linear elongated conduits formed therethroughfor straightening the flow of the fuel from the inlet port. The conduitsof this body are preferred for delivering a mostly laminar flow to thecombustion point, which is desirable for the reasons discussed above. Ina still even further preferred feature, the turbulence reducingstructure further comprises a relatively thin diffuser positioned withinthe combustion chamber between the inlet port and the catalyticallyinactive body. The apertures of the turbulence reducing structure inthis further preferred feature comprises a plurality of holes formedthrough the diffuser for initially straightening the flow of the fuelfrom the inlet port. The advantage of this diffuser plate is that itprovides for an initial turbulence reduction of the fuel flow prior toreaching the inactive body. It should be understood that these preferredfeatures are in no way intended to be limiting on this first aspect ofthe invention and are merely being mentioned as preferred features thatmay or may not be incorporated into a device constructed in accordanceof this first aspect of the invention.

A second aspect of the present invention provides a flying insecttrapping device having an advantageous heat exchange/combustion device.The device is configured to be used with a fuel supply containingcombustible fuel. The device comprises a supporting frame; an insecttrap chamber carried on the supporting frame; and a combustion/heatexchanger device. The combustion/heat exchanger device comprises a pairof halves each formed from a heat conducting material and each having apartial combustion chamber portion and a partial heat exchanger portionformed integrally together. The partial combustion chamber portions eachhave a partial combustion chamber formed therein and the partial heatexchanger portions each have a partial heat exchange path formedtherein. The pair of halves of the combustion/heat exchanger device arecoupled together such that (a) the partial combustion chamber portionsare coupled to define a combustion chamber portion of the device and thepartial combustion chambers are coupled to define a combustion chamberextending through the combustion chamber portion and (b) the partialheat exchanger portions are coupled to define a heat exchanger portionand the partial heat exchange paths are coupled to define a heatexchange path extending through the heat exchanger portion. Thecombustion chamber has an inlet port for connection to the fuel supplyto enable the fuel to flow into the combustion chamber for continuouscombustion to create an exhaust gas that includes carbon dioxide withinthe combustion chamber. The heat exchange path is communicated to thecombustion chamber and has an exhaust port opposite the inlet port toenable the exhaust gas to flow through the heat exchange path to theexhaust port. The heat exchange portion is constructed such that theexhaust gas flowing out from the combustion chamber flows along the heatexchange path to the exhaust port and a temperature of the exhaust gasis reduced as the gas flows along the heat exchange path via conductionthrough the heat conductive material of the halves of thecombustion/heat exchanger device.

An exhaust outlet is carried on the frame and is communicated with theexhaust port of the combustion/heat exchanger device. This allows theexhaust gas to flow outwardly therefrom so that insects attracted to thecarbon dioxide in the exhaust gas will fly towards the exhaust outlet.An insect inlet is communicated with the insect trap chamber to enableflying insects to enter the trap chamber through the insect inlet. Avacuum device communicated to the insect inlet is constructed andarranged to draw insects attracted to the exhaust outlet through theinsect inlet and into the insect trap chamber.

The advantage of this second aspect of the invention is the cost-savingsand assembly time reduction achieved by using a combustion/heatexchanger device comprising a pair of halves as described above.Specifically, in comparison to the device disclosed in the '243 patentthis construction reduces the number of parts and the assembly timerequired during manufacturing. The device disclosed in the '243 patent,while functioning effectively, has a high part count and its assemblysteps are likewise relatively time consuming. The provision of thecombustion/heat exchanger device as described above greatly reduces thepart count and therefore the corresponding assembly time, which leads toa lower overall cost structure for the device.

Other objects, features, and advantages of the present invention willbecome apparent from the following detailed description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates the distribution of dengue fever throughout theworld in the year 2000;

FIG. 1B is a comparative illustration of the recent increase of denguefever incidents in the Americas;

FIG. 1C illustrates the distribution of confirmed and probable humanLaCrosse encephalitis cases between 1964 and 1997 in the United States;

FIG. 1D illustrates the distribution of confirmed and probable human St.Louis encephalitis cases between 1964 and 1998 in the United States;

FIG. 1E illustrates the distribution of confirmed and probable humanWestern equine encephalitis cases between 1964 and 1997 in the UnitedStates;

FIG. 1F illustrates the distribution of confirmed and probable humanEastern equine encephalitis cases between 1964 and 1997 in the UnitedStates;

FIG. 2 is a perspective view of a device constructed in accordance withthe principles of the present invention;

FIG. 3 is a front elevational view of the device of FIG. 1;

FIG. 4 is a perspective view of a top shell of the housing of the deviceof FIG. 1;

FIG. 5 is a perspective view of the housing of the device of FIG. 1 withthe top shell removed;

FIG. 6 is an exploded view of the components associated with thehousing;

FIG. 7 is an exploded view of a combustion/heat exchanger device used inthe device of FIG. 1;

FIG. 8 is a perspective view of a right half of the combustion/heatexchanger device of FIG. 7 taken from the exterior thereof;

FIG. 9 is a perspective view of a right half of the combustion/heatexchanger device of FIG. 7 taken from the interior thereof;

FIG. 10 is a perspective view of the left half of the combustion/heatexchanger device of FIG. 7 taken from the exterior thereof;

FIG. 11 is a cross-sectional view taken along line A—A of FIG. 12;

FIG. 12 is a top view of the sleeve used in the combustion/heatexchanger device of FIG. 7;

FIG. 13 is a cross-sectional view taken along line B—B of FIGS. 11;

FIG. 14A is a cross-section of the diffuser plate taken along line C—Cof FIG. 14 and FIG. 14B is an isolated view of subject matter shown inFIG. 14A.

FIG. 15 schematically illustrates the layout of components within thecombustion/heat exchanger device;

FIG. 16 is an exploded view of an outlet nozzle of the device of FIG. 1and the components associated therewith; and

FIGS. 17-19 are an exemplary flow chart of a controller in accordancewith the principles of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

FIG. 2 is a perspective view of an exemplary flying insect trappingdevice, generally indicated at 10, constructed in accordance with thepresent invention. The device 10 is designed to be used with a supply ofcombustible fuel, such as a propane tank 12 of the type conventionallyused by consumers for supplying fuel to a barbecue grill. Broadlyspeaking, the general function of the device 10 is to emit an exhaustgas with an increased carbon dioxide content to attract mosquitoes andother flesh biting insects that are attracted to carbon dioxide. Then,an inflow, draws the attracted insects into a trap chamber within thedevice, whereat the insects are captured and killed by poison ordehydration/starvation. Alternatively, a user engaged in the study ofinsects may opt to not kill the captured insects and instead may removethem from the device 10 prior to dying for purposes of live examination.Regardless of the specific insect capturing purpose the user has inmind, the overall function of the device 10 is to attract and captureflying insects. The specifics of how the present invention operates toachieve this broad general function is discussed hereinbelow.

The device 10 comprises a supporting frame structure, generallyindicated at 14. The supporting frame structure 14 includes a housing 16supported on a set of legs 17. In the illustrated embodiment, two legs17 are used to support the housing 16. The supporting frame structure14, however, may have any construction or configuration suitable forcarrying the operative components discussed herein below, for example atripod arrangement may also be used. Additionally, the frame may includewheels 15, as shown in FIG. 2 and the aforementioned U.S. Pat. No.6,145,243, the entirety of which is hereby incorporated into the presentapplication by reference. Further, the supporting frame structure 14 mayalso include a supporting deck 19 for carrying the propane tank 12, sothat the tank 12 and device 14 can be transported together as a unit, asis also shown in FIG. 2 and the '243 patent.

The housing 16 includes a bottom shell 18 and a top shell 20 mountedthereto. The shells 18 and 20 are coupled and secured together usingconventional fasteners, adhesives, a snap-fit relation, or in any othersuitable manner. In the illustrated embodiment, these shells 18 and 20are molded from plastic; however, these shells 18, 20, and the housing16 in general, may be made from any materials and may take any shape,configuration, or construction.

A tubular intake nozzle 22 protrudes downwardly from the bottom shell 18and is formed integrally therewith. The intake nozzle 22 has a flaredlower end 24 which is attached by fasteners or snap-fitting to, and thusforms a part of, the intake nozzle 22. The flared lower end 24 definesan insect inlet 26. As will be appreciated from the details providedhereinbelow, a vacuum is applied to the nozzle 22 and the insectsattracted to the carbon dioxide emanated by the device 10 will be drawninto the insect inlet 26 for capture. The intake nozzle 22 and the inlet26 provided thereby may be carried on the supporting frame structure 14in any suitable matter and the construction illustrated and described isonly an exemplary construction. Thus, other configurations may be used.

Concentrically mounted within the intake nozzle 22 is an outlet nozzle28. The outlet nozzle 28 provides an exhaust outlet 30 on the lower endthereof. The function of the outlet nozzle 28 and its exhaust outlet 30is to allow a “plume” of exhaust gas comprising carbon dioxide to flowoutwardly and downwardly therefrom. As the downward flow of the exhaustgas reaches the ground, it flows radially outwardly from the device 10along the ground. Mosquitoes and other insects attracted to carbondioxide away from the device 10 will be able to sense this radiatedplume of carbon dioxide and follow the same to its source, namely theexhaust outlet 30. As can be appreciated from the constructiondisclosed, because the outlet nozzle 28 is concentric with the intakenozzle 22, the attracted insects will follow the carbon dioxide to itssource (i.e., the outlet 30) and thus they will be immediately adjacentthe insect inlet 26 upon reaching the outlet 30. As a result, theattracted insects will fly directly into the vacuum zone created by thevacuum communicated to the intake nozzle 22 and its insect inlet 26whereby they are drawn into the device 10 and captured therein. Therespective flows of the vacuum intake and the exhaust gas outflow areindicated by the inflow and outflow arrows in FIG. 3. For furtherdetails and variations on this aspect of the disclosed construction,reference may be made to the above-incorporated '243 patent. Also,reference may be made to U.S. Pat. No. 6,286,249 filed Sep. 17, 1996,the entirety of which is hereby incorporated into the presentapplication by reference.

The upper shell 20 of the housing 16 includes an access door 32 that canbe moved between open and closed positions to open and close an accessopening 34 formed in the housing wall. The access door 32 and the accessopening 34 opened and closed thereby is best illustrated in FIG. 4. Thedoor 32 is pivotally mounted to the upper shell 20 to facilitate itsopening and closing movements by inserting pivot pins 36 at the upperend thereof into openings (not shown) formed in the upper shell 20adjacent the upper edge of the opening 34. In the broader aspects of theinvention the door 32 may be entirely separable from the housing 16, ormay be connected for opening and closing movements using any suitableconstruction. In fact, the provision of the door 32 is not necessary atall and is simply a feature for convenience. A deformable gasket 38 isattached along the periphery of the opening 34 to provide a seal betweenthe door 32 and the periphery of the opening 34. The role of the accessdoor 32 and its associated opening 34 is to enable a user to gain accessto the interior of the housing 16.

As will be described in further detail below, a mesh bag 40, theinterior of which defines an insect trap chamber, is removably mountedwithin the housing 16. The chamber defined by the bag 40 is communicatedto the insect inlet 26 so that the insects drawn in by the vacuum willbe deposited in the bag 40 whereat they will become dehydrated andperish. Alternatively, the material of the bag 40 may be treated with apoison for purposes of facilitating the insect termination function;however, that is not a necessary feature of the invention. The accessdoor 32 and its associated opening 34 permit access into the interior ofthe housing 16 to allow the user to access the mesh bag 40 as desiredfor purposes of removal/replacement. Also, as another alternative, aplastic box or any other suitable structure may be used in place of meshbag 40. In the disclosed embodiment, the door 32 is formed from atransparent material to enable to user to visually inspect the bag 40 todetermine whether it needs removal/replacement. Specifically, thetransparent material enables to user to visually verify whether the bag40 is at or near its fill capacity of insects. In the broader aspects ofthe invention, the door 32 need not be transparent, and further, asmentioned previously, the device does not necessarily require the door32 and its associated opening 34.

FIG. 5 shows a perspective view of the components internal to thehousing 16, with the bag 40 and the upper shell 20 removed for clarity,and FIG. 6 shows an exploded view of these components. These internalcomponents include a combustion/heat exchanger device, generallyindicated at 50, a fan plenum 52, an electrically powered fan 54, and apartition structure 56. The bottom shell 18 includes a series ofintegrally molded ribs 58 defining a relatively flat area for mountingthe combustion/heat exchanger device 50. Further, the bottom shell 18also includes a pair of openings 60, 62. Opening 60 is provided forallowing a regulator hose 64 to be inserted therein and connected to thecombustion/heat exchanger device 50 for purposes of supply combustiblefuel, preferably propane, thereto. Opening 62 is provided forfacilitating connection of the electrical power supply cord 66 (shownwith a standard outlet plug 68 on the distal end thereof) to thecontroller 70, as shown in FIG. 6. The controller 70 is mounted on topof a partition structure 59. The partition structure also serves tosupport a grid barrier or baffle 57 which is provided to prevent themesh bag 40 from contacting the fan 54. Additionally, a duct 56 iscommunicated between the mesh bag 40 and the intake nozzle 22 to providea continuous flow path from the inlet 26 to the mesh bag 40. Further, afilter 61 is provided to ensure the air that is passed over thecombustion/heat exchanger device 50 is exhausted out of the device 10.The filter is constructed of a metallic mesh fabric, however, morebroadly, any suitable filtering method would be acceptable.

Referring now to FIG. 7, the combustion/heat exchanger device 50comprises a pair of halves 72, 74 each formed from a heat conductivematerial, such as steel or any other metal. These halves 72, 74 arefastened together by a series of fasteners, such as the threaded capscrew 76. Alternatively, welding or other fastening arrangements may beused. In the illustrated embodiment, the halves 72, 74 are each castfrom steel, but any suitable heat conductive material or method offorming may be used. Each half 72, 74 has a partial combustion chamberportion 78, 80 each defining a partial combustion chamber 82, 84 (seeFIG. 9 for partial chamber 82), and a partial heat exchanger portion 86,88 each defining a partial heat exchanging path 90, 92 (see FIG. 9 forpartial path 92). During assembly, the two halves 72, 74 are coupledtogether such that such that (a) the partial combustion chamber portions78, 80 are coupled to define a combustion chamber portion 94 of thedevice 50 and the partial combustion chambers 82, 84 are coupled todefine a combustion chamber, generally indicated at 96, extendingthrough the combustion chamber portion 94 and (b) the partial heatexchanger portions 86, 88 are coupled to define a heat exchanger portion98 and the partial heat exchange paths 90, 92 are coupled to define aheat exchange path, generally indicated at 100, communicated to thecombustion chamber 96.

The combustion chamber 96 has an inlet port 102. A fuel nozzle 104 isreceived in the inlet port 102. The nozzle 104 is of a conventional typeand has a spray angle of approximately 45 degrees. The spray nozzle 104is communicated to a solenoid manifold 106 (shown in FIG. 5) mounted onthe rear portion of the combustion/heat exchanger device 50 by anelongated tube 108. The proximal end of the regulator 64 (shown in FIG.6) connects to the solenoid manifold 106 and the manifold establishesfluid communication between the fuel supply (i.e. propane tank 12) andthe nozzle 104, thereby providing for delivery of the combustible fuelto the nozzle 104 and hence the combustion chamber 96. A solenoid valve110 moves between an open position for enabling the fuel to flow throughthe manifold 106 for delivery to the nozzle 104 and a closed positionfor preventing the fuel from flowing through the manifold 106, and thuspreventing it from flowing to the nozzle 104. The solenoid valve 110includes a spring (not shown) biasing the valve towards its closedposition. The solenoid valve 110 is electrically communicated to thecontroller 70 and the controller 70 normally transmits electricalsignals to energize the solenoid valve 110 and move it to its openposition when the power cord 66 is plugged into an electrical powersupply. Under certain operating conditions, as dictated by the controlscheme that is discussed herein below, the controller 70 will interruptthe aforementioned electrical signal in order to cause the spring tomove the valve 110 to its closed position for the purpose of preventingfurther fuel flow to the nozzle 104 and the combustion chamber 96.

The use of the solenoid valve 110 is a preferred feature and should notbe considered limiting.

Referring now to FIGS. 11-15, the combustion chamber 96 has a tubularsleeve 112 mounted therein. A relatively thin diffuser plate 114 ismounted within the sleeve 112 at the end thereof that is adjacent thenozzle 104. The diffuser plate 114 has a plurality of apertures 116punched therethrough, best seen in FIG. 14. The punching of theseapertures 116 forms a series of flanges 114 a extending outwardly fromthe downstream side (with respect to fuel flow) of the plate 114. Anuncoated, catalytically inactive ceramic monolith 118 is positionedwithin the sleeve 112 downstream from the diffuser plate 114 in spacedapart relation therefrom. The ceramic monolith 118 has a series ofelongated essentially linear conduits 120 formed through the lengththereof. These conduits 120 are best seen on FIG. 13 and in theillustrated embodiment there are 400 of them, although any amount may beused. Finally, a catalyst element 122 is positioned within the sleeve112 in spaced apart relation from the ceramic monolith 118. The catalystelement 122 includes a monolithic catalyst body 124 formed of ceramicand coated with a catalytically active material, such as platinum. Thebody 124 has a plurality of elongated essentially linear conduits formedthrough the length thereof in a fashion similar to monolith 1118. Thedistribution of these conduits are similar to those on the ceramicmonolith 118, except that in the illustrated embodiment there are 100conduits in the catalyst body, although any number may be used.

The tubular wall of the sleeve 112 has an igniter receiving hole 126formed therethrough and positioned between the catalyst body 124 and theceramic monolith 118. During assembly, the sleeve 112, with the plate114, monolith 118, and body 124 pre-assembled therein, is positioned inone of the partial combustion chambers 82, 84 prior to coupling the sametogether. Each of the partial combustion chamber portions 78, 80 has apartial igniter receiving hole 128, 130 formed on the upper edgethereof, which when coupled together define an igniter receiving hole.The igniter receiving hole 126 of the sleeve 112 is aligned with theigniter receiving hole defined by partial holes 128, 130 so that anigniter 134 can be inserted through the holes and positioned in betweenthe body 124 and the monolith 118. The igniter 134 is powered by theelectricity delivered from the controller 70 and creates a spark thatignites a fuel/air mixture flowing between the monolith 118 and thecatalyst body 124. During operation, as the fuel/air mixture continuesto flow to the catalyst body 124, the fuel/air mixture will becontinuously combusted. This region is referred to as the combustionpoint. The combustion point is located downstream of the monolith 118and the diffuser plate 114.

Broadly speaking, during operation, the catalyst body 124 is raised to atemperature that enables continuous combustion of the fuel/air mixturebeing delivered thereto. That is, at its operating temperature, thecatalyst body 124 is hot enough to burn the fuel/air mixture thereto,which in turn continues to maintain the catalyst body 124 at an elevatedtemperature. During combustion, the catalytically active material helpsto convert any carbon monoxide in the resulting exhaust gas to carbondioxide. The combustion may occur within the catalyst 24 or may occurbefore the catalyst body 24.

The combustion operation occurs as follows, with reference being madefor best understanding to FIG. 15. The fuel (i.e., propane) is sprayedinto the upstream end of the combustion chamber 96 and pressurized airis also forced into the upstream end of the chamber 96 for mixture withthe fuel. The manner in which the air is supplied will be describedbelow with reference to the function and operation of the fan 54 and thebeat exchanger portion 98, because the pressurized air is derived fromthe fan 54. This creates a turbulent mixture of fuel and air. At thispoint, turbulence is desirable to ensure that the fuel and air mixtogether thoroughly. However, turbulence is undesirable at thecombustion point. Thus, the diffuser plate 114 functions to initiallyreduce the turbulence and thus initially “straightens” the flow.Specifically, as the mixture flows downstream through the apertures 116formed through the plate 114, the apertures, and particularly theflanges extending downstream therefrom, function to “align” the mixtureflow in the downstream direction and reduce the turbulence thereof, thusmaking the flow somewhat more laminar. As the mixture continues to flowdownstream, it enters the conduits 120 of the ceramic monolith 118. Theelongated, essentially linear configuration of these conduits 120eliminates essentially all the turbulence and provides an essentiallylaminar flow of fuel/air mixture to the combustion point. Because thefuel and air have been thoroughly mixed upstream while in a highlyturbulent state, the mixture delivered by the monolith 118 to thecombustion point is essentially homogenous. A homogenous and laminarmixture flow is desirable for ensuring that all the fuel is burnedduring combustion. Specifically, a homogenous flow provides for evencombustion of all the fuel and air present at the combustion point andlaminar flow prevents “pockets” of unburned fuel from passing throughwith exhaust gas, as may happen if the mixture were highly turbulentduring combustion. This is desirable to avoid the presence of fuel inthe ultimate exhaust gas, as the presence of fuel is believed to beineffective at attracting flying insects, and in fact may be arepellent.

The air fuel mixture is burned by combustion to create a heated exhaustgas. This exhaust gas includes, among other things, carbon dioxide andsome carbon monoxide. As the exhaust gas flows through the catalyst body124, the catalytically active material causes a reaction to occurwhereby the carbon monoxide present in the gas is converted to carbondioxide. A by-product of this reaction, commonly referred to ascatalytic conversion, is also the creation of water (in vaporized form)in the exhaust gas. The manner in which this reaction occurs is wellknown and need not be described in further detail. The reason forproviding this reaction is to eliminate, as much as possible, thepresence of carbon monoxide in the exhaust gas, as it is known thatcarbon monoxide is a repellent to mosquitoes and other flying insects.The presence of water in the exhaust gas is an advantageous, althoughnot necessary, result of the catalytic conversion reaction because theresulting exhaust gas will better mimic the exhalation of a mammal,which is typically moist due to presence of water. The use of a catalystbody 124 with a plurality of elongated conduits is advantageous in thatit provides for increased exposure of the heated exhaust gas to thecatalytically active material coated thereon.

Broadly speaking, the plate 114 and the monolith 118 can be said toconstitute a turbulence reducing structure. The turbulence reducingstructure having a plurality of apertures, constituted by the conduits120 and the apertures 116 in the illustrated embodiment, oriented in thesame general direction as the conduits of the catalyst body 124. Asdiscussed above, these apertures are configured to straighten the flowof fuel from said inlet port to thereby reduce turbulence in said fuelprior to reaching the combustion point.

Preferably, an insulating material 130 is provided between both themonolith 118 and the catalyst body 124 and the interior surface of thesleeve 112.

The combustion chamber 96 has an exhaust port 136 downstream from thesleeve 112 that opens to the heat exchange path 100. The exhaust gasflows through the exchange path 100 to an exhaust outlet 138 of thecombustion/heat exchange device 50. As the gas flows along this path100, it transfers heat to the heat conductive material of the heatexchange portion 98. The heat exchanger portion 98 includes a pluralityof vertically oriented heat exchanging fins 140 separated by a pluralityof vertical openings 142. The heat transferred from the gas is conductedto these fins 140 and the fan 54 causes air to flow through the openings142 as described below. The air flowing through these openings 142 coolsthe fins 140 and absorbs the heat transferred from the exhaust gas.Optimally, the temperature of the exhaust gas as it exits the exhaustport 138 should be around ambient temperature and preferably no greaterthan 115° F. Even more preferably, the exhaust gas temperature should beno greater than 5-15 degrees Fahrenheit greater than ambient. As aresult, the end product of the process is an exhaust gas that is anexcellent simulation of mammalian exhalation—it contains carbon dioxide,moisture from the presence of water, and has a temperature around orslightly above ambient, which is typical of mammalian exhalations.Further, the catalytic conversion reaction minimizes or eliminates thepresence of carbon monoxide. Thus, the resulting exhaust gas is asuperior attractant for mosquitoes and other flying insects that prey onthe flesh or blood of mammals and that “home in on” mammalianexhalations to locate their prey.

The function and operation of the fan 54 will now be described. The fan54 is powered by an electrical signal delivered by the controller 70,which as mentioned above is powered by electrical power delivered bycord 66. The use of a power cord 66 for connection to an external powersource is not a necessary feature of the invention and the power fordriving the fan 54 and any other components may be derived from othersources, such as batteries, solar panels, or the conversion of thermalenergy from the combustion process into electrical energy, as isdisclosed in the above-incorporated '243 patent.

The fan plenum 52 mounts to the combustion/heat exchanger device 50 by aseries of fasteners or other suitable attachment means, such as anadhesive or snap fit features. The plenum 52 basically encloses one sideof the device 50 and provides a mounting point for attachment of the fan54. A large circular opening 144, which is best shown in FIG. 6, in theplenum 52 allows the fan 54, which draws air from the insect intake port26 through the duct 56 and the opening 34 for the mesh bag 40, to causeair to flow from the fan 54 through the opening 144 and to the openings142 of the combustion/heat exchanger device 150 and out the filter 61.Thus, the fan 54 functions to both cool the fins 140 and create thevacuum for drawing insects into the insect intake port 26. However, anydevice suitable for creating a vacuum may be used and the provision of asingle fan 54 is just one example of a suitable vacuum device. Further,in the broadest aspects of the invention, the same device need not beused to both create the vacuum and supply air to the combustion chamber.

On the forward portion of the plenum 52 is an air supply portion 146that couples over a corresponding air supply portion 148 on thecombustion/heat exchanger device 50, also shown in FIG. 6. As can beseen in FIG. 9, portion 148 has an upper opening 150 that communicateswith the upper portion of the combustion chamber 96. Also, as can beseen in FIG. 7, portion 148 has a lower opening 152 that communicateswith the lower portion of the combustion chamber 96. Opening 152 opensto the downstream side (relative to the airflow drawn by the fan 54) ofthe device 50 through opening 142 a (shown in FIG. 10) and thus iscommunicated with the filter 61. Opening 150 opens to the upstream sideof the device 50 through the air supply portion 148 thereof and thuscommunicates with the fan plenum 52 and the fan 54. As a result of thisconstruction, the fan 54 enables ambient air to be delivered to thecombustion chamber 96 by forcing ambient air through the chamber 96 viaopenings 150 and 152. At that juncture, the air forced in as such mixeswith the fuel delivered by nozzle 104 for combustion according to theprocess described above.

FIG. 16 illustrates the outlet nozzle 28, which in the illustratedconstruction is removable, although removability is not a necessaryfeature. The upper end of the nozzle 28 has a pair of lug receivingslots 154 that are each essentially L-shaped. These lug receiving slots154 enable the nozzle 28 to be mounted to the lugs 156 provided on theinternal periphery of the exhaust outlet port 138 for thecombustion/heat exchanger device 50. These lugs 156 can be best seen inFIGS. 9 and 10. The nozzle 28 is mounted by aligning the open ends ofthe slots 154 with the lugs 156, moving the nozzle 28 axially upwardlyuntil the lugs 156 reach the bottom of the slots 154, and the rotatingthe nozzle 28 in a clockwise direction.

A supplemental insect attractant element 160 is mounted in the lower endof the nozzle 28. The insect attractant element 160 includes a housing162 and a cap 164 for closing the open bottom end of the housing 160.The cap 164 has snap-in elements 165 for releasably securing it withinthe housing 22. The attractant used inside the housing may be octenol orany other material that mimics a mammalian smell that will assist inattracting mosquitoes and other flying insects. The housing 162 has aplurality of openings 166 for enabling the attractant to mix with theexhaust gas and become part of the exhaust flow. The housing 162 has apair of internally threaded portions 168 that align with openings 170 onthe nozzle 22. A pair of screws 172 are inserted into these openings andinto the threaded portions 168 to releasably attach the housing 162.When the user desires, the attractant can be removed and replaced asneeded by removing the nozzle 28 and opening the cap 164 to access thehousing interior.

Referring now to FIGS. 17-19, the controller 70 is described withreference to the exemplary flow charts in accordance with the principlesof the present invention. When the flying insect trapping device 10 isturned on, as shown by 202, the controller 70 turns on the fan 54 andperforms a diagnostic check on the fan at 204. If the diagnostic checkof the fan fails or the fan 54 fails to turn on, the controller 70 willstop the system 10 and provide an indication to the user that there wasan error with the fan 54. Once the fan 54 is on and the diagnostic testsfor the fan have been passed, the controller 70 waits for time0 asindicated by 206 and opens the solenoid 110, turns on the igniter 134and performs a diagnostic test of the rest of the system at 208. Thediagnostic test of the rest of the system includes, for example, testingthe igniter, the thermister, the solenoid, the bug bag switch, etc.Again, if the diagnostic test at 208 fails, the controller will providean indication to the user as to which test failed, as indicated by 222.

Next the controller 70 checks the temperature of the system at 210 andas indicated at 212 if a temperature T1 is reached within 7 minutes theprocess continues. However, if the temperature T1 is not reached within7 minutes, the process continues to 224 where the fan 54 remains on fortime2, the solenoid 110 is closed, the igniter 134 is closed, the systemon function is disabled for time2, and the controller 70 indicates tothe user that there is no gas in the tank. If the temperature check at212 is passed then the igniter is turned off at 214 and at 216, thetemperature of the system is checked again. If a temperature T2 isreached within time4 the process continues to 218 where the controlleroperates in a normal mode and periodically checks the temperature,otherwise the controller goes to the operation described above at 224where it indicates to the user that there is no gas in the tank 12.

Under the normal operating mode 218, the controller makes sure that thetemperature is between T2 and T3. If it is, the system continues tooperate normally. Otherwise, the system 10 enters a temperaturemaintenance process as described with reference to FIG. 18.

FIG. 18 shows two possible situations that may occur if the temperatureof the system is not between T2 and T3. The first case 228, is that thetemperature of the system has increased above T3. In this situation, thecontroller 70 will turn off the solenoid for time2 as indicated by 230.Next, as indicated by 232, the solenoid 110 is turned on, the igniter134 is turned on, and the controller checks the system temperature. Ifthe system temperature does not increase to T1 within time 1 (asindicated by 234), the controller will indicate to the user that the gastank is empty, as previously described with respect to 224. If thetemperature does increase to T1, the igniter 134 is turned off and thecontroller 70 checks the temperature, as indicated by 236. Again, if thetemperature of the system does not reach 12 within time3, as indicatedby 238, operation 224 of indicating that the gas tank 12 is empty willoccur. If the temperature T2 is reached in time, the controller willmake ensure that temperature T3 is not reached for time4 (shown as 240)and return the system to normal operating mode 218. However, if thetemperature does increase above T3 within T4, the fan will remain on fortime2, the solenoid 110 will be closed, and the controller will notifythe user that the temperature is too high.

The second case, 244, is when the temperature of the system 10 is below12. In this case, the igniter 134 turns on and the controller 70 checksthe temperature of the system 10, as indicated by 246. At 248, if thetemperature of the system is increasing, the controller 70 returns thesystem to the normal operating mode 218. Otherwise, the controller 70indicates to the user, as previously described, that the gas tank 12 isempty.

FIG. 19, illustrates an exemplary control for turning the system 10 off.When the system 10 is turned off, as indicated by 302, the controller 70will leave the fan 54 on for time2, close the solenoid 110, close theigniter 134 and disable the on function for time2, as indicated by 304.

The temperatures described above are, in the above exemplary embodiment,600, 800, and 1000 degrees Fahrenheit for T1, T2, and T3 respectively.With regard to the times, time0, time1, time2, time3, and time 4 are 3,2, 5, 4, and 5 minutes respectively. The temperatures and times givenabove are only exemplary and the present invention should not be limitedto these values. In fact, any value can be chosen for these times andtemperatures.

Broadly speaking, the controller can perform a variety of functions andthe functions described above are intended to be one example of severalcontemplated methods of operation for the controller 70. In general, thecontroller 70 should operate the system 10 and the operation need notcontain each of the steps shown in FIGS. 17-19 or described above.

The foregoing illustrated embodiment has been provided to illustrate thefunctional and structural principles of the present invention and is notintended to be limiting. To the contrary, the present invention isintended to encompass all alterations, additions, substitutions andequivalents within the spirit and scope of the following appendedclaims.

1. A method for making a flying insect trapping device, said methodcomprising: providing a supporting frame; providing a combustion/heatexchanger device comprising a pair of halves each formed from a heatconducting material and each having a partial combustion chamber portionand a partial heat exchanger portion formed integrally together, saidpartial combustion chamber portions each having a partial combustionchamber formed therein and said partial heat exchanger portions eachhaving a partial heat exchange path formed therein; coupling said pairof halves of said combustion/heat exchanger device together such that(a) said partial combustion chamber portions are coupled to define acombustion portion of said device and said partial combustion chambersare coupled to define a combustion chamber extending through saidcombustion chamber extending through said combustion chamber portion and(b) said partial heat exchanger portions are coupled to define a heatexchanger portion and said partial heat exchange paths are coupled todefine a heat exchange path extending through said heat exchangerportion, said combustion chamber having an inlet port for connection tothe fuel supply to enable the fuel to flow into said combustion chamberfor continuous combustion to create an exhaust gas that includes carbondioxide within said combustion chamber, said heat exchange path beingcommunicated to said combustion chamber and having an exhaust portopposite said inlet port to enable the exhaust gas to flow through saidheat exchange path to said exhaust port, said heat exchange portionbeing constructed; such that said exhaust gas flowing out from saidcombustion chamber flows along said heat exchange path to said exhaustport and a temperature of the exhaust gas is reduced as the gas flowsalong said heat exchange path via conduction through the heat conductivematerial of said halves of said combustion/heat exchanger device;providing an exhaust outlet on said frame in communication with theexhaust port of said combustion/heat exchanger device, said exhaustoutlet being configured to allow said exhaust gas to flow outwardlytherefrom so that insects attracted to the carbon dioxide in saidexhaust gas will fly towards said exhaust outlet; providing an insectinlet in communication with said insect trap chamber to enable flyinginsects to enter said trap chamber through said insect inlet; andproviding a vacuum device on communication with said insect inlet, saidvacuum device being constructed and arranged to draw insects attractedto said exhaust outlet through said insect inlet and into said insecttrap chamber.
 2. A method according to claim 1, further comprising:prior to coupling said halves together, positioning a catalyst elementdisposed between said partial combustion chambers such that, when saidhalves are coupled together as aforesaid, said catalyst element ispositioned downstream of a point at which said continuous combustionoccurs, said catalyst element being formed from a catalytically activematerial that, during operation, converts carbon monoxide in saidexhaust gas to carbon dioxide as said exhaust gas flows therethrough andinto said heat exchanger path.
 3. A method according to claim 2, furthercomprising: prior to coupling said halves together, positioningturbulence reducing structure between said partial combustion chamberssuch that, when said halves are coupled together as aforesaid, saidturbulence reducing structure is positioned between the point at whichsaid continuous combustion occurs and said inlet port, said turbulencereducing structure having a plurality of apertures oriented in the samegeneral direction as the conduits of said catalyst body, said aperturesbeing configured to straighten the flow of fuel from said inlet port tothereby reduce turbulence in said fuel prior to reaching said combustionpoint.
 4. A method according to claim 3, wherein said catalyst elementand said turbulence reducing structure are positioned within a sleeveand said sleeve is positioned between said partial combustion chambersso as to simultaneously position said catalyst element and saidturbulence reducing structure between said partial combustion chambersprior to coupling said halves.